Wimbledon 2017, Day 4 highlights: David beats Goliath, flying Grigor Dimitrov and much more

Progressing to the third round, Roger Federer and Novak Djokovic had their first full matches in this year's Wimbledon after their opponents in the first round retired with an injury.

The third seed and tournament favourite Karolina Pliskova was the biggest upset on a day that saw 17th seed American Jack Sock and his 23rd seed compatriot John Isner getting ousted from the tournament.

However, the victories and defeats were not a bigger story than the horrific injury to American wildcard Bethanie Matterk-Sands who clutched on to her right knee and cried for help after suffering an 'acute knee injury'.

As we look ahead to Day 5 of Wimbledon, here are a few off-court highlights from Day 4 at SW19

As temperatures reached 30 degrees Celsius (86 degrees Fahrenheit), a lady collapsed in the stands on Court Three during the match between Juan Martin del Potro and Ernests Gulbis, holding up play for 25 minutes while paramedics waited for a stretcher.

"He made another reference just now in the gym about Starvin Lee Marvin or something like that. I've heard of Starvin Marvin. He references some more '80s bands, stuff like that."

— Coco Vandeweghe on learning from her new coach, the 1987 champion Pat Cash.

"I was just being honest with myself. I think I'm a good tennis player, and I've never had great result on grass."

—Gael Monfils, into the third round, still thinks he has not played a decent game on grass.

"I always see the board out there and see my name. Every year I take a picture and every year my coach goes, 'Grigor, you take the same picture every single year'. I say, 'I don't know. I think it's cool'."

— Grigor Dimitrov on the ninth anniversary of him winning the Wimbledon juniors.

Stats of the Day

589 - Latvia's Ernests Gulbis becomes the lowest-ranked player in the third round of a Grand Slam since Richard Krajicek (# 1,093) in 2002

24 - The number of men aged 30 or over competing in the second round, equalling the Open-era record at Wimbledon set in 2016.

0- Since defeating Nicolas Mahut 70-68 in the fifth set at Wimbledon 2010, John Isner has not won a single five-setter at the Wimbledon